The present invention relates to molten metal sampling, i.e. to a method and apparatus for extracting samples of metal from a bath of molten metal, for evaluation as by chemical analysis.
In the production of metals and alloys, it is frequently necessary to take samples of their melts for evaluation. Analyses, for example, are routinely performed to check on purity or constitution, so as to guide the metallurgist in taking corrective action. A particular need for evaluating melts routinely exists when continuously casting.
Commonly, samples for analysis are removed from a bath of molten metal by means of a lance which is lowered or plunged into the metal from above. The lance is plunged through the slag or flux layer and the sample taken by the lance could, therefore, be contaminated. Moreover, the use of a plunging lance may be restricted to taking samples from relatively shallow depths within the metal, so the samples obtained for evaluation may not be representative of the melt as a whole. Further, the lances are quite substantial and costly implements, have limited service lives and require quite elaborate equipment for manipulating them in the hostile environment above the molten metal bath.